content = """

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# 第一大题

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# 1.字符串的编码
>>> "你好".encode("utf-8")
b'\xe4\xbd\xa0\xe5\xa5\xbd'

# 2.字符串的解码
>>> b = "你好".encode("utf-8")
>>> b.decode("utf-8")
'你好'

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# 第二大题

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# 1.Create（创建）
>>> a = "a"
>>> a += "b"
>>> a
'ab'

# 2.Retrieve（检索）
# 根据索引
>>> a = "Hello World"
>>> a[1]
'e'

# find（获取目标字符的索引值）
>>> a = "hello world"
>>> a.find("e")
1

# startswith和endwith
# startswith
>>> f = "2020-11-22-xxxxx"
>>> f.startswith("2020-11-22")
True

# endswith
>>> f = "xxx.jpg"
>>> f.endswith(".jpg")
True

# 3.UPDATE（更新）
#replace（替换）
>>> a = "hello werld,hello werld"
>>> a.replace("wer","wor")
'hello world,hello world'

# split（分割）
>>> a = "<<python>>,<<java>>,<<c++>>"
>>> a.split(",")
['<<python>>', '<<java>>', '<<c++>>']

# join（拼接）
>>> b
['<<python>>', '<<java>>', '<<c++>>']
>>> ",".join(b)
'<<python>>,<<java>>,<<c++>>'

# 4.DELETE（删除）
# strip
>>> a = "      hello,world    "
>>> a.strip()
'hello,world'

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# 第三大题

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# 1.按传入参数默认顺序
>>> a = "ping"
>>> b = "pong"
>>> "play pingpong:{}{}".format(a,b)
'play pingpong:pingpong'

# 2.按指定参数索引
>>> a = "ping"
>>> b = "pong"
>>> "play pingpong:{0},{1},{0},{1}".format(a,b)
'play pingpong:ping,pong,ping,pong'

# 3.按关键词参数
>>> "play pingpong:{a},{b},{a},{b}".format(a="ping",b="pong")
'play pingpong:ping,pong,ping,pong'

# 4.按变量
>>> a = "ping"
>>> b = "pong"
>>> f"play pingpong:{a},{b}"
'play pingpong:ping,pong'

# 5.小数的表示
>>> "{:.2f}".format(3.141596)
'3.14'

"""